diff options
Diffstat (limited to 'arch/x86/mm/fault_64.c')
| -rw-r--r-- | arch/x86/mm/fault_64.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c index c48d95c306df..75b7b165bdf3 100644 --- a/arch/x86/mm/fault_64.c +++ b/arch/x86/mm/fault_64.c @@ -223,6 +223,7 @@ KERN_ERR "******* Your BIOS seems to not contain a fix for K8 errata #93\n" KERN_ERR "******* Working around it, but it may cause SEGVs or burn power.\n" KERN_ERR "******* Please consider a BIOS update.\n" KERN_ERR "******* Disabling USB legacy in the BIOS may also help.\n"; +#endif /* Workaround for K8 erratum #93 & buggy BIOS. BIOS SMM functions are required to use a specific workaround @@ -230,10 +231,12 @@ KERN_ERR "******* Disabling USB legacy in the BIOS may also help.\n"; A lot of BIOS that didn't get tested properly miss this. The OS sees this as a page fault with the upper 32bits of RIP cleared. Try to work around it here. - Note we only handle faults in kernel here. */ - + Note we only handle faults in kernel here. + Does nothing for X86_32 + */ static int is_errata93(struct pt_regs *regs, unsigned long address) { +#ifdef CONFIG_X86_64 static int warned; if (address != regs->ip) return 0; @@ -249,9 +252,9 @@ static int is_errata93(struct pt_regs *regs, unsigned long address) regs->ip = address; return 1; } +#endif return 0; } -#endif static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs, unsigned long error_code) @@ -278,6 +281,26 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs, */ static int vmalloc_fault(unsigned long address) { +#ifdef CONFIG_X86_32 + unsigned long pgd_paddr; + pmd_t *pmd_k; + pte_t *pte_k; + /* + * Synchronize this task's top level page-table + * with the 'reference' page table. + * + * Do _not_ use "current" here. We might be inside + * an interrupt in the middle of a task switch.. + */ + pgd_paddr = read_cr3(); + pmd_k = vmalloc_sync_one(__va(pgd_paddr), address); + if (!pmd_k) + return -1; + pte_k = pte_offset_kernel(pmd_k, address); + if (!pte_present(*pte_k)) + return -1; + return 0; +#else pgd_t *pgd, *pgd_ref; pud_t *pud, *pud_ref; pmd_t *pmd, *pmd_ref; @@ -321,6 +344,7 @@ static int vmalloc_fault(unsigned long address) if (!pte_present(*pte) || pte_pfn(*pte) != pte_pfn(*pte_ref)) BUG(); return 0; +#endif } int show_unhandled_signals = 1; |